Oil supplies are growing and demand is slow because of the world's continuing economic problems. It would take a much larger conflict before U.S. consumers would feel a real jolt, according to DeHann.

Weakened alliances

With its support of Israel, the U.S. government finds itself on the opposite side from several of its allies in the Middle East. Egyptian officials have shown strong support for Hamas, and even more Westernized, business-minded Qatar has aligned with the group.

New Egyptian president Mohamed Morsi -- a member of the Muslim Brotherhood, which has long-standing ties with Hamas -- and others elevated by the Arab Spring are in particularly tenuous positions. They are trapped between their interest in keeping at least some ties with the United States and populations that are overwhelmingly anti-Israel.

A large number of civilian deaths in Gaza could increase radicalization in Arab and Islamic nations, pushing fledgling and besieged governments further from the U.S. It could also provide fresh recruits for terrorist groups in the region. Al Qaeda operatives and propaganda have cited the Palestinian situation as a motivation behind attacks.

An emboldened Iran

Iran has been one of the primary benefactors of Hamas, providing military training and the powerful Fajr-5 rockets that have been the top target of Israel's bombing runs.

A prolonged fight in Gaza could divert international attention away from Iran and its nuclear program.

"The New York Times's Tehran-based Thomas Erdbrink warned on Twitter. "While #Iran and #Hamas have been estranged over Syria, Iran's leaders will be highly upset over Jabari's assassination today in Gaza," he wrote. 'Forget ANY #Iran-US talks if conflict in Gaza escalates. ... #Iran leaders can never be seen as talking to US, while its 'eternal' ally Israel assassinates Iran's ideological allies.' "

Damage to hopes for a real peace between Israel and its neighbors

Bringing peace to Israel and its Arab neighbors is important to the United States for several reasons, not least of which is that the Palestinian cause has long been a beacon for terrorism. Hatred of Israel extends to its allies, chief among them the United States.

America's primary partner in the peace process, the Palestinian Authority government in the West Bank, looks feeble compared to Hamas. The perception hurts the chances of the U.S. government's preferred two-state solution.

"Hamas hasn't won yet, but if present trends continue it will be very difficult for the PA to fend off its further encroachment into the West Bank and ultimate seizure of control of the Palestinian national movement. ... For the West and Israel to starve, humiliate and strangle the PA, while Qatar, Turkey, Iran and even Egypt vie for Hamas's affections and seek to be kingmakers in Gaza, is producing precisely this effect."